1. Field of the Invention
This invention relates to heterocyclic quaternized nitrogen-containing cellulosic graft polymers and methods for their preparation. In another aspect the invention relates to the use of said polymers in skin and hair treating formulations.
2. Description of the Prior Art
Quaternized nitrogen-containing cellulose ether derivatives are well known and possess certain desirable properties. U.S. Pat. No. 3,472,840 describes their substantivity to many substrates. However, these quaternized compounds are strongly polar and lack lipophilic groups. Thus they are of limited use in compositions which are relatively incompatible with polar anionic polymers.
High charge density N,N-dialkenyl-N, N-dialkyl ammonium halide cellulosic graft polymers are disclosed in U.S. Pat. No. 4,464,523 and hydrophobe substituted, quaternary nitrogen-containing cellulose ether derivatives are the subject of U.S. Pat. No. 4,663,159. However, when employed in hair care, these polymers are not easily removed by shampoos and they tend to build up on the hair filaments giving a dull waxy appearance. On the other hand, the non-ionic cellulose ethers of U.S. Pat. No. 4,228,277 possess little substantivity in that they do not interact with ionic substrates such as the keratinous material of hair and skin.
An improved grafting monomer which contains both pyrrolidone and ammonium moieties is 2-methacryloxyloxyethyl[(l-pyrrolidonyl) methyl]ammonium chloride (MEPDAC) having the formula: ##STR1## U.S. Pat. No. 4,831,097 discloses such water soluble heterocyclic cationic graft polymers of cellulose containing both pyrrolidone and quaternary ammonium moieties grafted onto hydroxyethyl cellulose. This polymer was used as an antistat and conditioner in hair and/or skin preparations. The quaternary ammonium groups gave the product substantivity, but too many such groups made it difficult to remove from the hair by washing, resulting in build-up. On the other hand, increasing the number of pyrrolidone groups gave the product better compatability properties, permitting easier combing. However, this grafting monomer has only an equal number of pyrrolidone and quaternary ammonium moieties, which limit the effectiveness of the grafting.
Accordingly, it is an object of the present invention to provide polymers in which the ratio of pyrrolidone to quaternary ammonium groups in the grafting monomer can be predetermined to accommodate the particular hair product use intended for the graft polymer.
Another object of this invention to overcome the above deficiencies and to provide a substantive, mildly cationic cellulosic graft polymer particularly suitable for conditioning and cleansing of hair and skin and useful in all applications in which related quaternary nitrogen-containing cellulosic materials have been utilized previously.
These and other objects and features of the invention will become apparent from the following description and disclosure.